Ball valves are used in fluid couplings when high flow capacity and low flow restriction is desired. Generally, the ball valve is of a spherical configuration having a large diametrical bore extending therethrough and the valve is located within the flow passage of a coupling or fitting in a sealed manner and rotation of the valve 90.degree. fully opens or closes the valve. The spherical configuration of the ball valve is normally accommodated within the coupling configuration. A typical identical half coupling of this type is shown in the assignee's U.S. Pat. No. 4,438,779.
However, when it is desired to use valved couplings or fittings wherein low fluid spillage is required upon disconnection of the coupling parts ball valves are not employed as the spherical configuration of the ball valve causes voids to exist in the connection end face of the coupling wherein fluid is trapped and escapes to the atmosphere and earth upon disconnection of the coupling parts. When ball valves are employed with identical half or "unisex" couplings it is necessary to locate the ball valves inwardly from the associated coupling part connection end to prevent interference of the ball valve with the other coupling structure or valve and under conventional coupling constructions of the identical part type utilizing ball valves the requirement to inwardly locate the ball valves to prevent interference during valve operation creates fluid trapping cavity and voids rendering such couplings environmentally unacceptable when used with corrosive or toxic fluids, or highly concentrated fluids such as fertilizer. As the excellent flow characteristics of ball valves make this type of coupling highly desirable a significant need exists for ball valve couplings or fittings which have low spillage or fluid loss characteristics during disconnection, but previously, such coupling parts have not been available.